1. Field of the Invention
The present invention relates to a chip-on-suspension-type magnetic head device and a method for manufacturing a chip-on-suspension-type magnetic head device.
2. Description of the Related Art
Chip-on-suspension-type magnetic head devices have been known as magnetic head devices in which weak read-signals from magnetic heads are amplified directly by IC chips mounted on suspensions so that the effect of noises due to stray capacitance or stray inductance is reduced. In the chip-on-suspension-type magnetic head devices, IC chips which intervene in signal circuits between the magnetic heads and control circuits are mounted on and fixed to FPCs (flexible printed circuits) which connect the magnetic heads with the control circuits and which are disposed on the suspensions which support the magnetic heads.
When an IC chip is mounted on a suspension, it is necessary to protect the IC chip from the environmental influence (for example, heat and moisture) and impacts and to prevent the IC chip from spreading dust. An IC chip, which is generally made of a material such as Si or Ge, spreads Si or Ge dust when it is not sealed with a resin, whereby there is a risk in that a magnetic head for a hard disk is crushed.
Therefore, the IC chips fixed onto the suspensions have been hitherto sealed by piling up resins (adhesive) onto the upper faces of the IC chips. However, there has been a problem in that the thickness of the IC-chip parts is increased or the IC chips are partly exposed because of inaccurate thicknesses of the resin caused by simply piling up the resin onto the IC chips. When the thickness of the IC-chip parts is unnecessarily increased because of the excessively applied resin, for example, the size of the hard disk devices cannot be reduced and a risk occurs in that suspensions interfere with each other when a plurality of the suspensions are laminated in the thickness direction. When the IC chips are partly exposed because the amount of the resin is excessively small, the risk of spreading dust is increased.